umluse-caserup

UML Use case Specification for an Extended Use Case


I'm documentating a design, I have a doubt. The Use Case Specification RUP template have an extensión point section, and I was wondering if this section was meant to describe the extended use case or as I suppossed first, I have to make a specification of its own.

Someone please clarify this for me. Thanks in advance.


Solution

  • Please see this answer to understand what is an extended UC.

    UML, include, extend relationship

    Extension point is defined in the extended UC and specifies how/when exactly the extending UC can be invoked. As a UC is typically described by scenarios and scenarios have steps, you usually describe the extension point as steps in which the extension can occur.

    In the example I gave you, "Place order" is the extended UC and "Print Order" is the extending UC.

    Let's suppose the following scenario of the "Place Order": 1. User fills the form 2. User confirms the input 3. System validates the input 4. If ok, System registers the Order 5. If ok, System displays the confirmation message

    Another nice way to specify extension points is via activity diagram (if you want to avoid textual scenario descriptions).